123109809 has 16 divisors (see below), whose sum is σ = 166385664. Its totient is φ = 80960000.

The previous prime is 123109793. The next prime is 123109829. The reversal of 123109809 is 908901321.

It is a cyclic number.

It is not a de Polignac number, because 123109809 - 2⁴ = 123109793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 123109809.

It is not an unprimeable number, because it can be changed into a prime (123109829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 106384 + ... + 107534.

It is an arithmetic number, because the mean of its divisors is an integer number (10399104).

Almost surely, 2^123109809 is an apocalyptic number.

It is an amenable number.

123109809 is a deficient number, since it is larger than the sum of its proper divisors (43275855).

123109809 is a wasteful number, since it uses less digits than its factorization.

123109809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1608.

The product of its (nonzero) digits is 3888, while the sum is 33.

The square root of 123109809 is about 11095.4859740347. The cubic root of 123109809 is about 497.4669341592.

The spelling of 123109809 in words is "one hundred twenty-three million, one hundred nine thousand, eight hundred nine".